1. Field of the Invention
This invention relates to terminating ribbon cables and, more particularly, to a method and apparatus for preparing the free ends of flat electrical cable conductors and attaching such prepared free ends to electrical connectors.
2. Description of the Background Art
The development of new electrical cables in which a large number of wires are encapsulated in a flat insulating web has produced significant advantages in computers, telecommunication devices and the electronics industry generally. These cables are presently manufactured with conductors formed as fine parallel wires located on closely spaced centerlines. Such wires may be used for transmitting either electrical power or electrical signals.
Along with the obvious advantages of size reduction, wire separation and identification, and general ease of handling, such flat cables also present disadvantages. For example, the fineness of the wires and the closeness of their spacing generally increase wire handling difficulties during termination of the cable ends, i.e., during the stripping of the insulation from the ends of the wires, during the identification and bending of preselected wires and during the attaching of the individual wires to electrical components such as connectors. The development of even smaller cables with finer, more closely spaced wires, further aggravates these problems. This, in turn, further complicates cable end termination including the interconnection of such cables to their connectors. Additionally, when flat cables are used for signal transmission purposes, the closeness of wire centerlines dictates their positioning at specific, precise, constant locations for a particular application if the accurate transmission of signals is to be accomplished. The background art discloses many connectors for ribbon cables as well as many techniques for preparing ribbon cable ends and attaching such prepared ends to connectors. Note, U.S. Pat. No. 4,260,209 to Zell which discloses an insulation displacement connector with a slotted beam and an application tool for providing mass termination of a pre-stripped ribbon cable. There is, however, no teaching or suggestion of selective wire bending or soldering of selective wires of the ribbon cable to the terminals of the connector. Shatto U.S. Pat. No. 4,367,909, like the patent to Zell, discloses an insulation displacement connector with a slotted beam but employs a plurality of funnel entries at one end to guide the conductor wires to new centerlines. Again, such disclosure does not teach or suggest any method or apparatus for conveniently and accurately bending such wires selectively to facilitate their positioning nor does it disclose soldering wires to a connector. The Bricker patent, U.S. Pat. No. 4,451,099, also discloses an insulation displacement connector with a slotted beam. There is no disclosure of any associated method or apparatus for the preparation of the cable ends or for coupling of the prepared cable ends to a connector. Lastly, Feldman U.S. Pat. No. 4,616,893 discloses a connector for board-to-board coupling. Such disclosure, however, does not teach or suggest any method or apparatus for preparing ribbon cables nor any method or apparatus for use in coupling ribbon cables with associated connectors.
None of these patents discloses a method or apparatus for efficiently stripping and bending the wires at the ends of a ribbon cable and attaching such stripped and bent wires of the ribbon cable to connectors as herein disclosed. Further, there is no background disclosure of a method or apparatus capable of terminating the ends of ribbon cables wherein such ribbon cables have wires are as small as 0.008 inches in diameter as contemplated by the present invention. This is significantly smaller than wires previously employed. Such significantly reduced wire diameters will allow for the proportionate reduction in the spacing between centerlines to 0.0125 inches along with a proportionate increase in the number of wires per ribbon cable to 81 wires per linear inch.
No background patent or other background disclosure teaches or suggests the efficient, convenient, accurate, and economical cable terminating method and apparatus as described herein. Known methods and apparatus are simply lacking in one regard or another.
As illustrated by the background disclosures, efforts are continuously being made in an attempt to connect electrical elements of ever decreasing size. No prior effort, however, suggests the present inventive combination of method steps and component elements arranged and configured for terminating the fine, closely spaced wires at the stripped end of a ribbon cable as disclosed and claimed herein. Prior methods and apparatus do not provide the benefits attendant with the present invention. The present invention achieves its purposes, objectives and advantages over the prior methods and apparatus through a new, useful and unobvious combination of method steps and component elements, through the use of a minimum number of functioning parts, at a reduction in cost to manufacture and operate, and through the utilization of only readily available materials and conventional components.
These objects and advantages should be construed as merely illustrative of some of the more prominent features and applications of the present invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or by modifying the invention within the scope of the disclosure. Accordingly, other objects and advantages as well as a fuller understanding of the invention may be had by referring to the summary and detailed description of the preferred embodiment of the invention in addition to the scope of the invention as defined by the claims taken in conjunction with the accompanying drawings.